Electrical fire alarm



21, 1956 J. FEUSSN-ER 2,760,030

ELECTRICAL FIRE ALARM Filed Oct. 24, 1952 INVENTOR.

JACOB FEUSSNER United States Patent Ofiice 2,760,030 Patented Aug. 21, 1956 ELECTRICAL FIRE ALARM Jacob Feussner, Freeland, Pa.

Application October 24, 1952, Serial No. 316,597

2 Claims. (Cl. 200-=-137) The present invention relates to fire alarms and more particularly has reference to an electrically actuated alarm responsive immediately upon the existence of an abnormal heat condition in the area containing the alarm to effect an audible or visual signal or both thereby warning the occupants or owners of the building or other structure equipped with the alarm.

The alarm assembly may be installed in residences, oflice buildings, barns or any other type of enclosure, the number of individual alarm assemblies installed being dependent upon the area of the enclosure.

An important object of the present invention is to provide an electrically actuated fire alarm unit which includes but few essential working elements thereby enabling the unit to be inexpensively manufactured and maintained.

Yet a further object of the invention is to provide a fire alarm of the character described wherein the alarm assembly can be pre-set to become effective at any desired temperature.

Still another object of the invention is to provide an electrically actuated fire alarm assembly wherein the movable contact element is moved into engagement with the fixed contact element by the expansion of a metal strip operatively associated with the movable contact element due to the existence of an abnormal heat conditon.

And still a further object of the invention is to provide a fire alarm, the working parts of which can be readily contained in compact housing thereby allowing the unit to be easily transported, stored and when installed, the unit consumes but little space.

Additional and more detailed objects and advantages of the invention will appear from the following description and accompanying drawing illustrating a preferred embodiment of the invention. The invention consists in the novel features and arrangements as may be depicted and described in connection with the assembly shown.

In the drawings wherein like reference characters denote the same or similar parts and in which:

Figure 1 is a front elevational view of the assembly with the door of the housing in the open position, the view being partly shown in cross-section.

Figure 2, being a sectional view taken along the lines 2-2 of Figure l, the view looking in the direction of the arrows, and

Figure 3 is a sectional view taken along the line 33 of Figure l, the view looking in the direction of the arrows.

The alarm assembly comprises a housing of suitable material such as wood, access being had to the interior of the housing by means of a door 11 hinged to one of the walls of the housing as shown at 12. The door is maintained in the closed position by the locking unit denoted 13 and a handle 14 is provided on the top wall to permit the assembly to be carried. In addition, suitable means is carried by the housing whereby it may be mounted on the wall of a room or the like.

A thermometer of conventional type 14 is supported by the rear wall of the housing adjacent one of the end walls and means for permitting the assembly to operate at a predetermined temperature cooperates with the thermometer, such means being indicated generally 15. The means 15 includes an externally threaded rod 16, the upper and lower ends of which engage threaded openings in brackets 17 and 18 respectively. A metal block 19 is carried by the rod is and the block supports an indicator finger 20 and a contact element 21. A knurled nut 22 is provided on the rod 16 in proximity to the upper end thereof and by the proper manipulation of the nut the block 19 will move either upwardly or downwardly respecting the thermometer. Hence, the alarm may be readily and easily set to operate at any desired temperature, it being understood that the pointer finger 20 should be lined up with proper graduation on the thermometer scale. Also, the temperature should be sufficiently above the normal room or enclosure temperature to prevent any possibility of the assembly functioning except when the abnormal heat condition occurs.

A bracket 23 is supported by the top wall of the housin and is provided with a forked portion 24. A rod member 25 is pivoted to the forked portion as shown at 26 and the rod terminates at one end in a contact 27. Hence, the contact 21 constitutes the fixed contact while the contact 27 is the movable contact. The opposite end of the rod member is formed with a counterweight 28.

A standard 29 is attached to the lower wall of the housing and an arm 30 is pivoted to the upper end of the standard as depicted at 31 and the free end of the arm 31, is connected to the rod member 25 by means of a link, the ends of which are coupled to an eye 32 on the rod member and an aperture 33 in the arm, the link being denoted 34.

One end of a spring 35 is secured to the arm 30 as shown at 36 and a rod 37 is attached to the opposite end of the spring as at 38. The rod projects through an opening in the lower wall of the housing and is threaded for receiving a nut 40. A cage 41 preferably of wire mesh is fixed to the lower wall of the housing and a pair of expansible metal strips 42 are mounted within the cage, and a non-expansible strip 43 is located between the strips 42. It will be seen that the lower strip 42 bears against the nut 40 while the upper strip 42 bears against the nuts surrounding the rod 37. The threaded portion of the rod 37 extends through apertures (not shown) in the strips. When the heat conditions are such as to expand the strips 42, the upper strip bears against the upper nuts and the lower strip 42 will apply a force to the nut 40 and thus move the rod 37 downwardly which through the arm 30 and the link 34 will move the rod member 25 upwardly about its pivot 26 to enable the contact 27 to engage the contact 21.

Normally, the contact 27 is held out of engagement with the contact 21 and the distance between the respective contacts can be adjusted by manipulating the nut 40. Needless to say, the contact 27 should be in close proximity to the Contact 21 so that upon the abnormal heat condition arising in the room, substantially instantaneous contact is made.

The current for actuating the assembly is supplied by connecting the electric leads (not shown) to jacks 41A and 42B on the top wall of the housing and conductor 43 runs from the jack 41A to the block 19, the conductor including a coil section 44 to allow the conductor to move with the block during its adjustment on the rod 16.

The leads to the audible or visual alarm (not shown) such as a bell, light or both are connected to jacks 45 and 46 and a conductor 4'7 is coupled to the jacks 42B and 46. Conductor 48 having a coil section 49 extends from the jack 45 and is suitably secured to the rod member 25.

While the operation is believed apparent from the fore-- going description, it may briefly be summarized as follows;

The block 19 is moved by the operation of the nut 22 until the finger 20 is opposite the desired graduation at which the alarm is to become effective. The nut 40 is next turned so as to move the contact 27 to a point Where it Willi clear the contact 21 on the block 19 and the assembly is now ready for use.

If a fire starts in the room in which the unit is installed, the heat generated thereby will cause the strips to expand whereupon the rod will pull the arm 30 in a downward direction which downward movement will, through the link 3'4 move the rod member 25 in an upward direction thereby engaging the contacts 21 and 27. This completes the circuit to the bell or other indicating device.

The contact arrangement is such that the alarm is effective substantially immediately upon the existence of the abnormal heat conditon whereby it is possible to take the necessary steps to extinguish the fire before it has an opportunity to make much progress.

The alarm bell or light can be located in the same room as the housing or it may be mounted at any suitable site. Also, the alarm bell may be a central station in situations where an assembly is mounted in each room of the building.

I claim:

1. A switching means for an electrically actuated fire alarm of the type having a housing, and a thermometer mounted within the housing, such switching means including an indicator finger movable to a desired temperature reading on the said thermometer, a contact element on the finger, a movable contact element, means normally maintaining the movable contact element out of engagement with the first named contact element, and heat expansible means operatively connected to the said means to overcome the action of said means when an abnormal heat condition arises to move the movable contact element into engagement with the first named contact element to complete a circuit to an indicator device.

2. A switching means for an electrically actuated fire alarm of the type having a housing, a thermometer mounted within the housing, and a block movable longitudinally of the thermometer, such means including an indicator finger on the block to denote the desired temperature reading on the thermometer, a contact element on the block, a pivotally mounted rod member, a contact on the rod member, spring means operatively connected to the rod member normally maintaining the contact out of engagement with the contact element, and heat expansible means operatively connected to the spring means operative upon the existence of an abnormal heat condition to overcome the action of the spring means and move the rod member about its pivot to bring the contact thereon into engagement with the contact element on the finger to complete a circuit to an indicator device.

References Cited in the file of this patent UNITED STATES PATENTS Re. 17,993 Denison Mar. 10, 1931 464,957 Corman Dec. 15, 1891 655,317 Wilder Aug. 7, 1900 751,362 Ward Feb. 2, 1904 

